/*
 * @(#)MethodInvoker.java	1.0 Apr 26, 2008
 *
 *	The MIT License
 *
 *	Copyright (c) 2008 Malachi de AElfweald <malachid@gmail.com>
 *
 *	Permission is hereby granted, free of charge, to any person obtaining a copy
 *	of this software and associated documentation files (the "Software"), to deal
 *	in the Software without restriction, including without limitation the rights
 *	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *	copies of the Software, and to permit persons to whom the Software is
 *	furnished to do so, subject to the following conditions:
 *
 *	The above copyright notice and this permission notice shall be included in
 *	all copies or substantial portions of the Software.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *	THE SOFTWARE.
 */
package org.eoti.reflect;

import java.util.*;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class MethodInvoker
{
	protected Object toInvokeUpon;
	protected String methodName;
	protected ArrayList<InvocationParameter> params;

	public static Object invoke(Object toInvokeUpon, String methodName)
		throws IllegalAccessException, NoSuchMethodException, InvocationTargetException
	{
		MethodInvoker mi = new MethodInvoker(toInvokeUpon, methodName);
		return mi.invoke();
	}

	public MethodInvoker(Object toInvokeUpon, String methodName)
	{
		this.toInvokeUpon = toInvokeUpon;
		this.methodName = methodName;
		this.params = new ArrayList<InvocationParameter>();
	}

	public void addParam(Class cls, Object obj)
	{
		params.add(new InvocationParameter(cls,obj));
	}

	public Object invoke()
		throws NoSuchMethodException, IllegalAccessException, InvocationTargetException
	{
		if(params.size() == 0)
		{
			Method method = toInvokeUpon.getClass().getMethod(methodName, new Class[]{});
			return method.invoke(toInvokeUpon, null);
		}

        Class[] classes = new Class[params.size()];
		Object[] objects = new Object[params.size()];
		int i=0;
		for(InvocationParameter param : params)
		{
			classes[i] = param.getParamClass();
			objects[i] = param.getParamObj();
			i++;
		}

		Method method = toInvokeUpon.getClass().getMethod(methodName, classes);
		return method.invoke(toInvokeUpon, objects);
	}
}
